1. Field of the Invention
This invention relates to vibration dampers. More specifically, the invention is a compact vibration damper that can be tuned.
2. Description of the Related Art
Structural vibrations frequently need to be damped to prevent damage to a structure. To accomplish this, a standard linear damper or elastomerically-suspended masses are used. A linear damper includes a piston housed in a fluid-filled cylinder. A connecting rod couples a structure to the piston, such that structural vibrations are coupled from the rod to the piston whose linear movement is damped by the fluid in the cylinder. The problem associated with a linear damper is the space required for its construction. For example, if the damper's piston has to be capable of 2 inches of movement in either direction, the internal length of the fluid-filled cylinder would have to be at least 4 inches while the connecting rod must be at least 4 inches to span the piston's travel. This means that the overall length of the linear damper is at least 8 inches to achieve +/−2 inches of damping movement. Unfortunately, not all applications have the space to accommodate the size requirements of a linear damper. Further, tuning this type of damper typically involves changing the fluid in the cylinder. This can be a tedious and/or messy operation.
In the case of masses suspended using elastomeric materials (i.e., those whose material strain exhibits a viscous force), the allowable range of motion is severely restricted by the allowable strain of the elastomeric material. In addition, tuning of this type of damper requires a complete replacement of the elastomeric materials, which can be involved depending on their placement.